Access to the roofs of commercial buildings, or other elevated structures, is frequently provided by means of a separate extension ladder. The base of the ladder rests upon the ground or other foundation below the roof line and the upward portion of the ladder rests against the edge of the roof or protruding edge of a like structure.
Although ladders often provide treads on their base for traction at the base end, they are not permanently affixed, and the base of the ladder, when weight is on the ladder, may slide, either sideways or outwardly, resulting in instability, downward sliding of the ladder, and possible injury to any person using the ladder. Likewise, at the roof's edge, the surfaces may not be conducive to holding the ladder in one spot and, again, when a person is using the ladder, particularly with heavier loads or when weight shifts take place when gaining access to, or exiting from, a roof, forces may be exerted on the ladder to cause it to move sideways or downwardly, again providing instability and possible injury.
Habitually this problem has been dealt with, somewhat, by having a second person holding the base of the ladder. Even this, however, may not be sufficient if enough force is exerted at the top of the ladder to cause the ladder to move when a person at ground level has a poor purchase point, in terms of being a fulcrum, to prevent motion caused by significant force at the upper end.
Attempts in the prior art to address the issue of an unsecured upper extending end of a conventional ladder include the ladder port and ladder dock designs produced by Ladder Tech LLC. These include a variety of wall mount configurations each including a generally “L” shaped horizontal bracket aligning with an edge of the structure and with a pair of elongated abutments with upward curved outward ends affixed in laterally spaced and forward projecting fashion to a horizontal support edge associated with the “L” shaped bracket.
Selected variants of the Ladder Tech design further include upper vertically extending handhold supports as well as lower vertically and horizontally crosswise extending reinforcing members. A plurality of mounting tabs extending from the lower members further include apertures for receiving such as bolts for securing to wall support locations associated with the elevated structure. The lower mounting members can further include depth extending dimensioning supports to offset the ladder support bracket from such as a gutter.
Inman, U.S. Pat. No. 8,439,163, teaches a ladder safety device including a gutter guard, a ladder extender, a ground spike and a ladder show for improving the stability of a ladder placed against a structure with or without gutters. Davis, Jr., US 2013/0199874, teaches a ladder safety apparatus and method including a stabilizer bar for a top portion of a ladder, the stabilizer bar being configured to rest on a peaked roof top. A balance rail is provided for the top portion of the ladder to provide substantially upright handles for a user to grasp when the ladder is positioned on the roof top. The safety apparatus may be engaged to a ladder using one or more engagement rods.
Yet additional ladder safety rest and stabilizing devices include each of those depicted in Von Hebestreit, U.S. D715,964, and Johnson, U.S. D706,953. In the case of Von Hebestreit, a planar support skirt adapted for seating upon an elevated edge of the structure interconnects a vertically extending portion including a pair of spaced apart and elevating upper most edges for seating the ladder therebetween.
In the further case of Johnson, a roof top supported and width extending rod in turn includes a pair of transverse abutment posts. A pair of clamping members are supported upon the posts and sandwich therebetween the elongated side or stanchion members of the ladder.